David Mercer's past consulting clients and customers include:
(confidential client identities replaced with descriptions)
IBM
Sun Microsystems
Netscape
Groupe Bull
NASDAQ
IslandECN
Banamex
Groupo Financiero Bital
NTT
Telmex
AlphaGraphics
One of the 3 largest banks in the US
One of the largest utilities in New York
Various supercomputing clients